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LI BRARY OF CONGRESS. 

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UNITED STATES OF AMERICA. 



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THE 



BOSTON MACHINIST. 

BEING A COMPLETE 

SCHOOL FOR THE APPRENTICE 

A8 WELL AS THE 

ADVANCED MACHINIST. 

SHOWING HOW TO MAKE AID ERY TOOL IN EVERY 

BRANCH OF TH1 SS. 

WITH A TKEATI8E ON 

SCREW AND GEAR CUTTING. 



ISy WALTER FITZGERALD, 

Inventor and Mechanical Engineer. 



NEW YORK: 
JOHN WILEY & SON, 535 BROADWAY. 

1866. i 



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Entered according to Act of Congress, in the year 1866, by 

JOHN WILEY & SON, 

In the Clerk's Office of the District Court of the United States, for 
the Southern District of New York. 




NEW YORK PRINTING OOMPAN1, 

81, 83, and 85 Centre St. 



CONTENTS. 



PAGE 

1. The Apprentice's first lesson. 9 

2. Lesson second 9 

3. Lesson third 11 

4. Lesson fourth 11 

5. Lesson fifth 19 

6. To drill a large hole in the end of a shaft 13 

7. Straightening Shafting ' . . 

8. Setting a Lathe straight to turn Shafting U 

9. Turning Shafting 15 

10. Setting a Lathe to turn Tapering 16 

11. Tools for different kinds of Turning 18 

12. Planer Tools 

13. Chucking Pulleys 23 

14. Setting the Chuck-rest 

15. To drill a hole where you have no Reamer 

16. Boring a hole with a boring tool. 

17. Squaring, or Facing up Cast Iron Surfaces 26 

18. Scraping Cast Iron smooth I 7 

19. Keep your Lathe clean. 27 



IV CONTENTS. 

PAGE 

20. Boring Holes and Boring Arbor 27 

21. To make a Boring Arbor and Tool, that will not 
Chatter 28 

22. Gearing a Lathe for Screw-cutting 29 

23. Cutting a Screw in an Engine Lathe 30 

24. Cutting Square Thread-Screws 31 

25. Mongrel Threads 32 

26. Planing Metals 33 

27. Planing perpendicularly 33 

28. Planing a Key-Way .33 

29. Planing a T-shaped Slat 34 

30. To Plane a Gibe-Rest or Slide 35 

31. Note 35 

32. Gear Cutting 36 

33. Depth of Teeth 36 

34. Measuring to find the Number of Teeth 37 

35. Bevel Gears 38 

36. The different Styles of Filing 39 

37. To File a Square Hole 40 

38. Draw-Filing and Finishing 40 

39. Lining Boxes with Babbitt Metal 40 

40. Making Lining Metal 41 

41. Putting Machines together 41 

42. Working Steel for Tools 42 

43. Annealing Steel 43 

44. Water Annealing 44 



CONTEXTS. V 

PAGE 

■\:>. Eardening Steel Tools of the various Kinds 44 

4G. Dipping tools when hardening 46 

47. Dipping a half-round file or reamer 40 

48. Dipping a fluted reamer properly 47 

49. Tempering tools 47 

60. Fancy tool making 48 

51. Making collets, or drill sockets 48 

52. To make a collet properly 49 

53. To make a collet for upright drills 50 

54. Making drills 50 

55. Spiral drills 60 

66. Cutting the Spiral Grooves 53 

67. Flat Drills for Chucking 54 

58. Tap and Reamer Wrenches 55 

59. Proportions for Tap and Reamer Wrenches 

60. Tap and Reamer Wrenches. Size two 56 

61. Tap and Reamer Wrenches, Size three 56 

62. Wrenches for Taps and Reamers, Size four 56 

63. Wrenches for Taps and Reamers, Size five 58 

64. Wrenches for Taps and Reamers, Size six 58 

65. Making Taps. The Turning 58 

66. Proportions of Screws 59 

67. Cutting the Threads 61 

68. Square Thread-screws 63 

69. Mongrel or half Y, half square Threads 63 

70. Fluting Taps 64 



VI CONTENTS. 

PAGE 

71. How to go to work 64 

72. Fluted Reamers , 67 

73. How to make a Fluted Reamer 67 

74 Half-round Reamers 71 

75. Rose Reamers 71 

76. Counter-boring Tools 72 

77. Making Dies for Screw-cutting 72 

78. Milling Tools 73 

79. Proportionate numbers of Teeth, in different Sizes. . .74 

80. Proportions of Broad Cutters 74 

81. Punches and Dies 76 

82. Making Gauges 77 

83. Note on Balance-wheels 77 

84. A few words as to Master Mechanics 78 



PREFACE 



In preparing this work, the author has endeavored 
to give to the Mechanic a volume that he can readily 
understand, though he may not have a full know- 
ledge of the scientific terms commonly used in works 
of this kind. He has also aimed to give a full ex- 
planation of every subject treated of in as few words 
as possible. He had thought of adding an article on 
the proper speed of turning and planing metals; but 
as they vary so much in hardness, it il almost impos- 
sible to lay down any safe rule, and he has therefore 
concluded to omit it. He hflfl llflO purposely omitted 
the subjects of Geometry and Machine Drawing, 
as they would have extended the volume beyond its 
proposed size; and, besides, there are already pub- 
lished many good treatises on these subjects. Ask- 
ing, therefore, that due allowance may be made for 
all omissions and imperfections, he submits his little 
work to the hands of those for whom it is intended. 

Boston, Feb. 21, 1866. 



THE BOSTON MACHINIST. 



1. Tlie Apprentice's first less* 
The first thing for the Apprentice to learn 
is: to clean and keep in order, the laf 
planers, drills, milling and slabbing niacin: 
This is done by brushing off the chips, 
then wiping them with a wad of cotton 
To clean a lathe, ran the carriage and pup 
head about four feet from the main head, then 
to keep the feed and gears dean, brush all the 
chips towards the carriage, and after doing this, 
wipe the head and wa\ in and oil tli 

Then, after cleaning the carriage and puppet- 
head, run them back to the main head, brush 
the chips from the lower end of the lathe, wi] e 
and oil the ways, and it is done. 

2. Lesson second. 

The next lesson is : to learn to trim cast- 
ings. This is done by chipping off the rough 



10 



THE BOSTON MACHINIST. 



:' 



m 




THE BOSTON MACIITNT 11 

places with a cold chisel and then filling them 
smooth with a second-hand file, which answers 
quite as well as a new one. 

3. Lesson third. 

The next thing to learn is, to centre bolts, 
shafts, etc. To do this, take a centre-punch 
and hammer, and punch it into the centre of 
each end of the shaft, or bolt as Dear the cen- 
tre as you can guess ; then find a pail of l" i nch 
centres and spring them apart, putting the 
points into the punch-marks you have mad- 
each end of the shaft. After doing this, take 
a piece of chalk in one hand and turn the 
shaft with the other, holding the chalk n 
enough to the sh; ir the ends, to touch the 

side that runs out. When yon have done this 
take the shall from the I the 

punch-mark towards the side marked by the 
chalk. Continue these operations till the shaft 
is true at the ends. 

4. Lesson fourth. 

Having learned to centre a shaft, you will 
now proceed and learn to drill the centres. In 
doing this, use a drill about one sixteenth of 



12 THE BOSTON MACHINIST. 

an inch in diameter. Put the drill into a hand 
lathe, and with one end of the shaft upon the 
centre, drill the other, continually turning it 
around while drilling. They should be drilled 
about one fourth of an inch deep. After 
doing this, countersink them with a three- 
square countersink, made for the purpose. 

5. Lesson fifth. 

You will now learn other modes of drilling, 
— the first being to drill holes through flat 
pieces of iron. In doing this they are first 
laid out a certain distance from the edges with 
a pair of dividers. Then make a punch, mark 
the distance from the edge or position where 
you wish to drill the hole. After marking this 
punch-mark, set your dividers the size you 
want to drill the hole, and strike a circle 
around the mark made by the punch. Having 
done this, proceed to drill the hole, taking 
great care to drill within the circle, and if your 
drill runs to one side, chip a piece out of the 
opposite side with a half round chisel, — this 
will bring the drill back to the centre of the 
circle. Continue this practice till the hole is 
perfectly true, and if you are careful at the first 



THE BOSTON MACHINIST. 13 

you will find no difficulty in drilling holes, and 
drilling them properly. 

6. To drill a large hole in 1 of a Shaft. 

This is only done when you have no chuck 
that will hold the shaft. To do it properly, 
drill a small hole the depth required with a 
straight spiral drill; or if you have none use a 
fiat one that is straight on the sides ; then fol- 
low with one or two more larger as may 
be required. The object of using a small drill 
first, is because being L re endwise on 
the drill it will not run out side- 

ild if the small hoi- i not drilled I 

In drilling with small drills, such utre 

drills, always speed up your drill 
will run. This prevents the breaking drills, 
and there is no danger of burning the points 
off, as some suppose, except the steel be very 
hard. 

7. Straightening i hg. 

Thi3 should be done by centring, as before 
explained ; then put into a lathe, and the ends 
squared up with what is called a side-tool. 
After doing this, take a piece of chalk and try 



14 THE BOSTON MACHINIST. 

it in several places, to find out where the worst 
crooks are ; then, if you have not a machine 
for springing shafting, spring it with a lever 
where the worst crook is, and continue this 
operation till the shaft is straight. 

8. Setting a Lathe straight to turn Shafting. 

First, see if your centres are true; if not, 
turn them up. For this purpose a square-end 
tool is best ; and they should always be kept 
true to a three-square gauge. Unless you do 
this, you will spoil about half your work, as 
many a one has done. After this is done, set 
your puppet-head so that it will turn the shaft 
straight ; and if it has no straight mark upon 
it, turn one end of the shaft for about an inch ; 
then, without moving your tools, take the 
shaft out of the lathe. Then run the carriage 
down to the main head, put your shaft into 
the lathe again, with the end which is turned 
towards the main head, and if the tool touches 
the place you have turned, the lathe is straight. 
If it does not touch, screw over the puppet- 
head, and keep trying it until your tool touches 
the place turned, at either end of the 
lathe. 



THE BOSTON MACHINIST. 15 

9. Turning Shafting, 

To do this properly, two chips should al- 
ways be run over the shaft, for the reason that 
it saves filing and leaves the shaft truer and 
more round; and on shafts thus turned, the 
time saved in filing more than compensates for 
the time lost in turning. Before you com- 
mence, you will put your feed-belts or gear on 
a coarse feed. Turn off one a sixty-fourth of 
an inch larger than the size required. Having 
turned off this chip, commence the finishing- 
chip, and turn it small enough to have the 
pulley-wring on about an inch without filing. 
This will leave it large enough to file and 
finish. If there are couplings to go on a shaft, 
with holes smaller than the holes in the pul- 
leys, the ends of the shaft, where they fit on, 
should be turned down to a sixty-fourth of an 
inch of the size desired before any part of the 
shaft is finished : that is, every part of a shaft 
should be turned to within a sixty-fourth of an 
inch of the size required, before any part of it 
has the finish-chip taken off. The reason for 
this is, that it leaves every part of the shaft 
perfectly true, which would not be the case 



16 THE BOSTON MACHINIST. 

were it done otherwise. Having done this, 
you will file the shaft so that the pulleys will 
slide on, and the couplings so that they will 
drive on, polish the shaft with a pair of polish- 
ing-clamps and some emery, and it is done. 

10. Setting a Lathe to turn Tapering. 

This is done by calculating the taper, a cer- 
tain amount to the foot or length of the piece 
to be turned. Therefore, if you have a shaft to 
turn a foot long, with one end one inch larger 
than the other, you will set your puppet-head 
over one-half inch, and you will get the re- 
quired taper of one inch to the foot. If you 
have a shaft a foot long, and wish to turn one- 
half of it tapering half an inch, you will set 
the puppet-head over half an inch, as before ; 
for the shafts being a foot long, you must cal- 
culate your taper from the length of the shaft : 
and if the taper is half an inch larger than six 
inches from the end, and the shaft exactly a 
foot long, the taper would be as before, one 
inch to the foot. If you have a shaft to turn 
that is twenty inches long, and you wish to 
turn it tapering two inches in its whole length, 
set your lathe over one inch, and this will give 






3. — A Right-hand Side Tool — side view. 
4. — A Left-hand Side Tool — top view. 
5. — A Round-ended Tool, for turning heavy shafting, 
cast-iron, etc. 

2* 



facing: 



18 THE BOSTON MACHINIST. 

you the taper required — two inches in twenty. 
If you have a shaft twenty inches long, and 
you wish to turn a taper half an inch in five, 
set your puppet-head over one inch, as before ; 
this will give you a taper of five inches in 
twenty, and half an inch in five ; because half 
an inch is one-fourth of two inches, and five 
inches is one-fourth of twenty. If you have a 
shaft twenty inches long, and want to turn it 
taper one inch in ten, set your lathe over one 
inch as before, and you have it ; for the shaft 
being twenty inches long and two inches taper 
in its whole length, it would be one inch only 
in half its length. 

11. Tools for different hinds of Turning. 

1. The best tool for squaring up the end of 
a shaft is what is called by machinists a side- 
tool. The best tool for turning small shafting 
is a diamond-point tool. 

2. The best tool to turn heavy shafting is a 
round-end tool, made to stand high like a dia- 
mond point, and to cut freely from the 
side. 

3. The best tool to turn a balance-wheel of 
cast-iron, or to square up any large surface, is 



ft. 



7. 



8. 




6. — Top view of a Screw-Tool, for cutting Y threads. 

7. — Side view of a tool for cutting Y threads. 

8. — A diamond-point Tool, for turning small shafting. 



9. 



10. 



11. 





9. — A Tool for cutting off a shaft ; is also used for cutting 

square thread-screws. 
10. — A Lath-boring tool. 
11.— A Tool for cutting a Screw inside a hole. 



THE BOSTON MACHINIST. 21 

also a round end tool, made well tapering to 
cut from the side. 

4. The best tool to cut off a shaft with is a 
tool made thin and having the tapering 
down, instead of up as in turning tools; this 
generally prevents their running in and break- 
ing. 

5. The best tool to bore out a hole is a lathe- 
boring tool with the end turned on a right 
angle to the left and the point turned up hook- 
ing. These tools bore far nicer than those 
made square on the top. 

6. The best tool with which to V 
thread-screw, is a V thread-tool with the points 
ground to lean down when finish, 

vents running and breaking >ol, or tearing 

the screw. 

7. In cutting a square thread, first use a 
square-point tool about three-fourths of the 
thickness of the thread you design to cut, i 
finish with one the size of the thread. The 
same rule applies when cutting a thread within 
a hole. 




12. — A Tool for planing a Key- Way. 



THE BOSTON MACHINIST. 23 

12. Planer Tools. 

The best tool for ordinary planing, is a half- 
side tool made short, and with the point turn- 
ed up, as an ordinary diamond point. 

The best tool for squaring up, is a round- 
point tool, cutting from the side. 

The best tools for planing under, as in slide 
rests, etc., etc., are sharpened up to a point, 
with the point turned up, and with a taper from 
the point to the body of about two inches. 

13. Chucking Pulleys. 

The term chuck, means to secure a piece of 
work in a certain position, so as to drill, or 
plane it true. The same name is given to the 
instrument employed in holding the pieces of 
w r ork. It is merely a round piece of iron, with 
a hole in one side of it, within which is cut a 
screw, for the purpose of securing it to the 
spindle of a lathe. On the side opposite, is a 
certain number of jaws, usually three or four, 
which screw together for the purpose of hold- 
ing a wheel, or other piece of work, while it is 
being drilled. In chucking a wheel or pulley, 
the first thing to be done, is to screw it into the 



24 THE BOSTON MACHINIST. 

jaws of the chuck, as near the position desired 
as you can guess. After doing this, screw a 
tool into the post, and set one end of it near 
the face of the pulley, then turn and adjust the 
wheel by means of the screws, until the tool 
touches it all round. After doing this, true 
the edges in the same way. And then, try the 
face again to see if it has moved. Some wheels 
are cast oblong, by the pattern's shrinking; 
and when wheels come this way, the proper 
mode of chucking them, is to set your tool 
against the face as before, turn and adjust the 
wheel so that it will touch the tool at two oppo- 
site points, then, with a rule, measure the two 
points farthest from the tool, and adjust them 
so they will be equal, and the wheel will be 
true. Some mechanics use a piece of chalk, 
but this is an improper way to true a wheel, 
even when it is perfectly round, for a wheel 
that is not chucked and drilled true, costs more 
time in turning than is needed to chuck and 
drill half a dozen wheels and pulleys, that are 
perfectly drilled, for patterns should be trued 
by the inside of the face and on the sides by 
the arms. 



THE BOSTON MACHINE 

14. Setting // resL 

In doing- th it into the tool-post with 

the middles of the slats through which the 
drill passes, exactly as high as the centres of 
your lathe, for if it is above or below the cen- 

. it will cut the hole larger than the drill, 
and thereby spoil the wheel. Havi the 

. you can proceed to drill the wheel. r l 
should be done with two drills, and where the 
holes are cored badly out of true, even tl 
should be used, it' you would 1. he hole 

perfectly true, and the last drill should only 
cut a chip one-sixteenth of an inch. This 
leaves a good and true hoi 

15. To drill a hole where y / 

It is Bometimes n< rill a hole of 

an exact size to fit a certain shaft, and at the 
same time have it smooth without reaming it. 
This may be done, by first drilling a hoi- 
one-hundredth of an inch smaller than the size 
desired, and then making a drill the size 

and running it through to finish with. This 
last drill should have the corners of its lips 
rounded, like a reamer, and the hole should be 
finished without holding the drill with a rest. 



26 THE BOSTON MACHINIST. 

16. Boring a hole with a boring tool. 

In boring a hole with a boring tool, it is 
usually necessary to drill the hole first, and too 
much care cannot be taken in finishing. An 
iron gauge should be made first; is usually 
made of a piece of sheet iron or wire. The 
hole should then be drilled smaller than the 
size desired, and then bored to the required 
size, and it is impossible to bore a hole perfect 
without taking two or three light chips, mere 
scrapings, with which to finish. Holes, in this 
way, may be bored as nicely as they can be 
reamed. 

17. Squaring^ or Facing up Cast Iron Surfaces. 

A round-end tool is best for this. A rough 
chip should first be taken off, over the entire 
surface to be faced. Then speed your lathe up 
and taking a light chip, merely enough to take 
out the first tool-marks, run over the entire sur- 
face again. In turning up surfaces it is always 
best to begin at the centre and feed out, as the 
tool cuts freer and will wear twice as long. 



THE BOSTON MACHINIST. 27 

18. Scraping Cast Iron smooth. 

To scrape cast iron, it is necessary to put a 
rest close to the surface to be scraped, and 
then with a thin wide scraper, commence by 
resting your scraper on one edge and scraping, 
twisting the scraper, and sustaining it while 
cutting, in your hand. You must not bear on 
hard, but scrape as light a chip as possible, and 
yon will have no trouble in scraping cast 
iron. 

19. Keep your Lathe ck 

I again remind you of keeping your lathe 
clean, and your centres in siiai unless you 

do this, you will soon spoil every arbor in the 
shop; and the wuvs of your lathe will be torn 
away, so as to be unfit to have any nice piece 
of work done upon them. 

20. Boring Holes with Boring Arbor. 
A boring arbor is a shaft with a steel tool 
in it, for the purpose of boring holes of great 
length, and is designed to be used in a lathe. 
In doing this properly, you must first see if 
your lathe is set straight. If not, adjust it ; 



28 THE BOSTON MACHINIST. 

having done this, put the piece of work to be 
bored in the carriage of your lathe, pass your 
arbor through the hole to be bored, and put it 
on the centres of your lathe. Having done this, 
adjust your work true to the position desired, 
by measuring from the point of the tool, con- 
tinually turning round the arbor from side to 
side of the piece to be bored, while you are 
bolting it to the carriage, and measure until it 
is perfectly true. Having done this, bore the 
hole, and take for the last chip only a hundredth 
of an inch. This makes a true and smooth 
hole. It is impossible to make a hole true with 
any kind of a tool when you are cutting a large 
chip, for the tool springs so that no dependence 
can be placed upon it. 

21. To make a Boring Arbor and Tool, that will 
not Chatter. 

Boring tools, when used in small arbors, are 
always liable to chatter and make a rough 
hole. To prevent this, the tool should be 
turned in a lathe, while in its position in the 
arbor, upon the circle of the size of the hole 
to be bored, and the bearing lengthwise of the 
arbor, should be only as wide as the feed of the 



THE BOSTON MACHINIST. 29 

lathe; for if the bearing of the tool is on the 
face, the more it will chatter. 

22. Gearing a Lattiefor Screw-cutting. 

Every screw-cutting lathe contains a long 
screw called the lead screw, which feeds the 
carriage of the lathe. While cutting screws, 
upon the end of this screw is placed a gear, to 
which is transmitted motion from another gear, 
placed on the end of the spindle. These gears 
each contain a different number of teeth, for 
the purpose of cutting different threads, and 
the threads are cut a certain number to the 
inch, varying from one to fifty. Therefore to 
find the proper gears to cut a certain number 
of threads to the inch, you will first: — mul- 
tiply the number of threads you desire to cut 
to the inch, by any small number, four for in- 
stance, and this will give you the proper g 
to put on the lead screw. Then with the same 
number, four, multiply the number of threads 
to the inch in the lead screw, and this will give 
you the proper gear to put on the spindle. 
For example, if you want to cut twelve to the 
inch, multiply twelve by four, and it will give 
you forty-eight. Put this gear on the lead- 

3* 



30 THE BOSTON MACHINIST. 

screw, then, with the same number, four, mul- 
tiply the number of threads to the inch in the 
lead-screw. If it is five, for instance, it will 
give you twenty. Put this on the spindle, and 
your lathe is geared. If the lead-screw is four, 
five, six, seven, or eight, the same rule holds 
good. Always multiply the number of threads 
to be cut, first. Some, indeed most small 
lathes, are now made with a stud geared into 
the spindle, which stud only runs half as fast 
as the spindle, and in finding the gears for 
these lathes, you will first multiply the number 
of threads to be cut, as before, and then multi- 
ply the number of threads on the lead-screw, 
as double the number it is. For instance : if 
you want to cut ten to the inch, multiply by 
four, and you get forty. Put this on the lead- 
screw, then, if your lead-screw is five to the 
inch, you will call it ten, and multiply by four, 
and it will give you forty. Again put this on 
your stud, and your lathe is geared ready to 
commence cutting. 

23. Cutting a Screw in an Engine Lathe. 
In cutting V thread-screw, it is only neces- 
sary for you to practise operating the shipper, 



THE BOSTON MACHINIST. 31 

and slide-screw handle of your lathe, before cut- 
ting. After having done this, until you get 
the motions, you may set the point of the tool 
as high as the centre, and if you keep the tool 
sharp, you will find no difficulty in cutting 
screws. You must, however, cut very light 
chips, mere scrapings, in finishing, and D 
take it out of the lathe often, and look at it 
from both sides, very carefully, to see that the 
threads do not lean, like fish-scales. After cut- 
ting, polish with an emery stick, and some 
emery. 

24. C'lft' 

In cutting square thread* 
necessary to get the depth required, with a tool 
somewhat thinner than one-half the pitch of 
the thiv After doing this, make another 

tool exactly one-half the pitch of the thr 
and use it to finish with, cutting a light chip on 
each side of the groove. After doing this, pol- 
ish with a pine stick, and some emery. 
Square threads, for strength, should be cut one- 
half the depth of their pitch, while square 
threads, for wear, may, and should be cut 
three-fourths the depth of their pitch. 



32 THE BOSTON MACHINIST. 

25. Mongrel Threads. 
Mongrel, or half-V, half-square threads, are 
usually made for great wear, and should be cut 
the depth of their pitch, and for extraordinary 
wear, they may even be cut one and a half the 
depth of their pitch. The point and bottom 
of the grooves should be in width one-fourth 
the depth of their pitch. What is meant here by 
the point of the thread, is the outside surface. 
And the bottom of the groove is the groove 
between the threads. In cutting these threads 
it is necessary to use a tool about the shape of 
the thread, and in thickness about one-fifth, less 
than the thread is when finished. As it is im- 
possible to cut the whole surface at once, you 
will cut in depth about one-sixteenth at a time, 
then a chip off the sides of the thread, and 
continue in this way, alternately, till you have 
arrived at the depth required. Make a gauge 
of the size required between the threads, and 
finish by scraping with water. It is usually 
best to leave such screws as these a little large 
until after they are cut, and then turn off a 
light chip, to size them. This leaves them true 
and nice. 



TBI DO01 LCHINIf 33 

26. P 

Ti tion in planii ) oil your 

planer and find out if the b -mooth. If it 

is not, file off the rough p] Then chs 

the they work well, and find out 

iments of the plan* After doing 
this, bolt your work on to the md if it is 

a long thin piece, plane off a chip, then I 

r and finish the oth< airing two 

chips, the last of which Id be very lij 

at care should be taken, in boltii i the 

. not to spring it. 
turn it to the otl and take off a I 

cut to finish it. 

27. P rly. 

In planing perpendicularly, it is n< y to 

swivel the bottom of the small head around, so 
it will stand about three-fourths of an inch in- 
side of squar ards the piece you an 
plane. This prevents breaking the tool when 
the bed runs back. 

28. Planing a Key- Way. 
To place a key-way in a shaft, it is necessary 
to first drill a hole, the size you intend to 



34 THE BOSTON MACHINIST. 

make the key-way, as deep as you want to 
plane. Then with a square point tool, plane 
the key- way a little narrower than you design 
to finish it down to the proper depth. After 
doing this, finish with a tool of the desired 
size. Some think it unnecessary to use two 
tools to plane a key-way, and argue that it takes 
more time. This may be the case, but it is 
impossible to plane a key-way with one tool, 
especially a narrow one, without tearing it, and 
again it is impossible to tell whether or not 
the tool will run under sidewise until you 
have planed the way its depth. Therefore if 
you first plane the way with a narrow tool, and 
it is found to run under, it is very easy to set it 
right in cutting out the finish chip. In setting 
a tool to cut a key-way, set a square on the 
planer-bed, and try both sides of it near the 
point, to see that it is perpendicular. This 
will usually prevent its running under. 

29. Planing a T-shaped Slat. 

In planing a T-shaped slat, or way, such as 
are used for slides, or on a planer bed, to hold 
the head of a bolt, it is first necessary to plane 
to the desired depth, with a square point tool, 



Till; BOSTON MACHINIST. 35 

and after doing this, plane the upper part of 
the way to the desired width. Having done 
this, plane the bottom part of the way with 
two tools, one bent on a right angle, and the 
other to the left. And in planing large w 
these tools should be made as small as they will 
Stand without breaking, and should cut freely 
on each of the three sides. Make a sheet iron 
gauge, and plane the way to it. In small shal- 
low ways they may be planed the depth and 
upper width at once, and then finished with 
one tool, made the desired shape of th 
This saves time. 

30. To Plane a Rest or Si 

Plane it all o\ I the slide, first on 

both Bides, then setting the planer head on an 

angle of thirty degrees, finish the slide with a 
taper point tool. 

31. Note. 

In planing metals, especially thin east iron 
surfaces, it is always necessary to plane over a 
cut on both sides, before finishing, either for 
the outside or scales. Being harder than the 
inside, the moment the scale is taken off the 



36 THE BOSTON MACHINIST. 

piece springs through the expansion of the 
scale on the opposite side. Hence the neces- 
sity of planing both sides before finishing 
either. 

32. Gear Cutting. 

In cutting gears, they are reckoned a certain 
number of teeth to the inch, measuring across 
the diameter to a certain line which is marked 
on the face or sides of the gear with a tool. 
This line is one half the depth of the teeth 
from the outer diameter. That is, if the teeth 
of the gear are two-tenths of an inch deep, this 
line would be one-tenth of an inch from the 
edge, and is called the pitch line. 

33. Depth of Teeth. 

Every gear cut with a different number of 
teeth to the inch, should be cut of a depth to 
the pitch line, to correspond with the number 
of teeth to the inch. This is called proportion. 
Therefore, if you cut a gear eight to the inch r 
the depth to the pitch line should be one-eighth 
of an inch, and the whole depth of the tooth 
would be two-eighths. Again, if you cut a 
gear twelve to the inch, the depth to pitch line 



TIIK BOSTON MACHINIST. 37 

ihould be one-twelfth of an inch, and the 
whole depth of tooth two-twelfths. A .an, 

if you cut a gear twenty to the inch, the depth 
to pitch line should be one-twentieth of an inch, 
while the whole depth should be two-twentie* 
and so on, ad infinitum. 

c)4. M to find tfu A 'h. 

To find the size a certain for 

a certain number of teeth, is ao I r if 

you study carefully these ru]. you v. 

a gear with thirty-two teeth and to the 

inch, it should g across 

the diameter to the pitch 1. I the two- 

itlis on itch line would mak 

four ii: od two-eighths, 

want a gear with iort; ., and ten to the 

inch, it ild m< the diam< 

to pitch line lour inches, and the Qthfl 

outside the pitch line would make the whole 
diameter four inches and t. And 

nn, if you want a gear with eighty teeth. . 
twenty to the inch, it should measure to the 
pitch line, across the diameter, four i . and 

the two-twentieths outside the pitch line would 
make it four inches and two-twentieths, and 

4 



38 THE BOSTON MACHINIST. 

these examples will form a rule for the mea- 
surement of all except bevel gears. 

35. Bevel Gears. 

These are turned a certain bevel to corre- 
spond with each other, according to the angle 
upon which the shafts driven by them are set. 
For instance, if two shafts are set upon an angle 
of ninety degrees, the surfaces of the faces of 
these gears will stand at an angle of forty-five 
degrees. To get the surface of these gears, in 
turning them, puts a straight edge across the 
face. Then set your level on an. angle of forty- 
five degrees, and try the face of the teeth by 
placing the level on the straight edge. After 
turning the face of the teeth, square the outer 
diameter by the face of the teeth ; and to get 
the size to which you wish to cut, measure 
from the centre of the face of the teeth. Thus, 
if a bevel gear is six inches in diameter, and the 
face of the teeth is one inch, you will measure 
from the centre of the face, and find it is five 
inches. On this line you calculate the number 
of teeth to the inch, and if you want a gear 
with twenty teeth, and ten to the inch, it should 
measure two inches across the face to the centre 



THE BOSTON MACHINE 39 

of the surface of the teeth ; and if the face of 
teeth were one inch in length, the diameter 
of the gear would be three inches, and the 
•jf the teeth would measure only one 
inch. Again, if you want to cut a gear with 
forty teeth, and ten to the inch, it would mea- 
sure four inches to the centre of the teeth on 
And if tl :ace of th 

inch long, the diameter of the g 
would be five inches, while it would oni 
sure three inches inside the teeth. These 
amplaa will form a rule for all rs. 

36. 7 Styles of 1 

To file a surfac it is n v on com- 

mercing, to - • the file tightly 1 

ir third and fourth li and the palm of 

your hands, until you become used to it. Your 
position in filing should be half I » to 

your work, with the middle of your foot 

fifteen inches behind vour left heel ; and to file 
your work true or square, it is d j to 

reverse your work often, as by this means you 
are enabled to see the whole surface you are 
filing, and to see, while filing, whether you are 
filing true or not. Where, however, your 



40 THE BOSTON MACHINIST. 

work is so heavy that you cannot reverse it, 
you had better file first to the right, and then 
to the left, as by this means you can plainly 
see the file marks, and this again assists you in 
filing true. 

37. To File a Square Hole. 

To file a hole square, it is necessary to reverse 
the work very often. A square file should first 
be used, and the holes finished with either a 
diamond-shaped file, or a half-round one. This 
leaves the corners square, as they properly 
should be. 

38. Draw-Filing and Finishing. 

To draw-file a piece of work smoothly and 
quickly, it is best to first draw-file it with a 
medium fine file, and finish with a superfine 
file. After doing this, polish the work with 
dry emery paper, and then with emery paper 
and oil. 

39. Lining Boxes with Babbitt Metal. 

To line boxes properly, so as to insure their 
filling every time, it is necessary to heat the 
box nearly red hot, or at least hot enough to 



Tin: BOSTON MACHINE 41 

melt the metal. Then smoke the shaft where 
metal is to be poured upon it. This insures 
its coming out of the 

cold. After smoking the shaft, put it into the 
box or boxes, and draw so: tty around the 

ends of them, for the purpose ing 

them, taking eare not to | upon it, for if 

you do it will go into the id fill a place 

that ought to be filled with Dl< nd in the 

iiitime your metal ought to I 
after you have poured it, let the ind till 

it is nearly cold; dri it your shaft, 

is done. 

40. Making L 

Melt in a crucible, one and a half | - of 

copper, and while the i is in. It:: 

in a ladle twenty-live pounds of tin, and three 

of antimony, Dearly red hot P<»ur the I 

together, and stir until nearly cool. This 

makes the finest kinds of lining metal. 

• 
41. Putti,, ^gdher. 

In putting machines together, no part should 
be finished except where it is i. :y to make 

a fit, as it is sometimes the case that machinery 



42 THE BOSTON MACHINIST. 

is miscalculated, and by finishing, it would be 
spoiled, while if it were not, it might be saved 
by slight alterations in design. And again, in 
finishing certain parts before you get a machine 
together, you are unknowingly finishing parts 
not necessary to be finished, and making them 
of a shape anything but desirable. This rule, 
however, is not intended to apply to machinery 
being made to detail drawings. 

42. Worhing Steel for Tools. 

In working steel for tools, great care should 
be taken to hammer ail sides alike, for if one 
side is hammered more than another, it will 
cause it to spring in hardening. Again, steel, 
when being hammered, should be heated as hot 
as it will stand, until finishing, and should 
then be hammered until almost black hot, for the 
reason that it sets the grain of the steel finer, and 
gives the tool a better edge. The reason for 
heating the steel so hot while hammering, is 
simply because it makes the steel tougher when 
hardened, and softer when annealed ; while if 
it were worked at a low red heat, the continued 
percussive shocks of the hammer w T ould so har- 
den it as to make it almost impossible to anneal 



TIIK BOSTON MACHINIST. 43 

it, and at the same time render it brittle when 
hardened. 

43. Anneah d. 

Tn annealing steel, it should be heated as 
slowly as possible to a red 1; at, but never hot 
enoi - scale, and Bhould then have two 

days or more " to cool in." Apiece of steel 
that is heated hot enough to SC r be 

annealed well, without working over, and is 
always rendered glassy, and bad to work, 
prove this, take a steel shaft and beat it in 
several places, hot enou 

ral oth Allow it to cool, 

and when you turn it, you will see at once 
that the places 1. | enough t<> . are 

considerably harder than t!. ated properly. 

All tools that are required t<> be hardened with- 
out springing. itters and reamers, should 
be turned to exactly one- fourth of an inch of 
their size, and then annealed before finishing. 
This takes the strains out, so that when they 
are heated for the purpose of hardening, they 
will not spring. 



41 THE BOSTON MACHINIST. 

44. Water Annealing. 

Heat the steel to a red heat, and let it lie a 
few minutes, until nearly black hot, then throw 
it into soap-suds. Steel, in this way, may be 
annealed softer than by putting it in the ashes 
on the forge. 

45. Hardening Steel Tools of the various Kinds. 

All steel tools should be hardened at a low 
red heat, or the lowest heat at which they will 
harden, and the larger a piece of steel is, the 
greater the heat required to harden it. This is 
on account of its taking longer to cool, for the 
moment a large body of heated steel is plunged 
into the water, the steam arising from the sur- 
face of the steel blows the water away from it, 
and thereby causes it to take more time in 
cooling. For instance, an anvil heated red-hot 
and thrown into a hogshead of water, would, 
instead of hardening, blow the water away 
from it and cool slowly, until the water boiled, 
and when taken out, would be as soft as before 
it was put in. Hence the necessity of harden- 
ing anvils under a jet of water, or a waterfall. 
Very small tools, as needles and centre-drills, 



THE BOSTON MACHINIST. 45 

penknives arid lancet-blades, should be harden- 
ed in oil, or in water slightly wan. by 
cooling in cold water, they cool too quid, 
and are either rendered brittle, or cracked, 
as to be worthless. This is also the case in 
hardening springs — they are almost invariably 
broken, when hardened in cold water, and 
therefore should be hardened in oil. I have a 
razor which, being too soft, I hardened in oil — 
after being concaved — without springing in 
the least, and it is now as good a I as I 
ever us«d. A piece of steel for a tool of any 
kind should never be 1 hot i h to 
raise Bcalea on ii pt where it is bo lai 

that it will not harden without ; j , when 

hardened at that heat, le in 

grain, and brittle, and you may draw the tem- 
per of it to a straw i nd it will still break 
more easily than a piece hardened at a 1 
heat, and not drawn at all, and at th 
time the piece that is heated hot enough to 
scale, and drawn, will be softer than the piece 
hardened properly. Hence it is necessary to 
take great care, in hardening steel for tools. 



boston mac: 



46. Dipping tools when hardening. 

To harden a penknife blade, lancet, razor, 
chisel, gouge-bit, plane, spoke-shave, iron-shav- 
ing knife, three and four-square files, and round 
and flat files, dip them endwise or perpendicu- 
larly. This keeps them straight, which 
would not be the case were they dipped, or 
put into the water otherwise. 






47. Dipping a half-round file or reamer, 

To dip a half-round file, or any tool that is 
solid, half-round, dip it with the half-round side 
twenty degrees leaning towards the water. 
This hardens it nearly straight. It is necessary 
here to remark that the surface of any piece of 
steel that is half round, has half as much 
again surface on the half round side to be 
hardened, as the flat side has, and the contrac- 
tion of the steel being equal, according to the 
surface, the necessity of dipping the half-round 
side at an angle, is apparent. That is a half- 
round surface tending to one point, which is, or 
has one and a half, the surface or power of con- 
traction, as the flat side. This contraction is 
what draws a piece of steel to one side, and 
makes it crooked. 



THE BOSTON" MACHINIST. 47 

48. Dipping a ftui ner property. 

Dip it perpendicularly to a short distance 
beyond the fluting — that is to bout half 

an inch, and withdraw and return it several 
times. This hardens all the lips, and prevents 
its cracking off at the water's edge, which is the 
case when a piece of steel is dipped in to a cer- 
tain depth, and allowed to cool without mov- 
ing. Arbors or mandrels are often broken off 
at the ends in this way, without the workman's 
knowing what caused them to era 

49. /" ' tools. 

Drawing the temper of tools, is usually done 
in a charcoal flame, and to draw the temper of 
a tool properly, it should be held in the thick- 
est part, or the part not requiring any t 
towards the lire, and in the meantime, should 
be often wiped with a piece of waste or a i 
dipped in oil. The oil the temper even, 

and prevents its drawing more in one place 
than another. And in drawing the temper of 
any tool it should be drawn very slowly, — 
otherwise it will run too for ere you are aware 
of it. Lancet-blades and razors should be 
drawn to a straw color. Knife-blades and 



48 THE BOSTON MACHINIST. 






chisels should be drawn to a copper or almost 
red color. Plane irons, shaving knives, and 
shoemakers' knives the same temper. Cold 
chisels and stone drills should be drawn to a 
dark blue. Fluted reamers should only be 
drawn to a straw color, on the end, as they 
never break elsewhere, and keep their size 
longer by leaving the lips hard. Half round 
or tapering reamers, also taps, dies, and drills, 
should be drawn to a straw color. Jijucs and 
gauges, also common lathe tools, need no draw- 
ing, being tempered enough when merely hard- 
ened. 



50. Fancy tool making. 

Probably no profession among the fine arts 
is more " scientific," or requires greater care, 
than the art of gun, and watch, or fancy tool 
making, and it is safe to say, that not one 
machinist in five hundred will make a good 
tool maker. We will now commence on — 

51. Malting collets, or drill sockets. 

The best collets for drill lathes are those 
which screw on to the spindle, and provided 
with a tapering hole, for the shank of the drill 
and a key-way, to. hold the end of the drill 



THE BOSTON MACHINIST. 49 

from turning. These collets are always true, 
and you have not the trouble bra .our 

drill whenever you use it, as with others. 
Collets for ordinary job shape, should be m 
with a set screw to hold the drills, and the I 
for the drill shank should be drilled to fit 
round drill steel, about seven- iths of an 

inch in diameter. This saves fitting the shanks 
of drills, and these drills are quit.,' asgoo« : 
drills made of forged steel. 

52. To maize a c rJy. 

For such collets as screw on to the drill lat I 
bore out the end and cut the fit the 

spindle well, and when you have done I 

screw it on the lathe v. 

After (loin drill a lid.' for the drill-shank 

about an inch and a quarter d iking care 

to drill it perfectly true, then ream i' 

Having done this, cut a key-way through the 

solid metal, below the bottom of, and running 

into the hole drilled for the shank. Th 

way should be half an inch long, and a fourth 

wide. It is intended to hold the drill, the end 

of which is filed flat. 

5 



50 THE BOSTON MACHINIST. 

53. To make a collet for upright drills. 

Drill the centres, and turn up the end to be 
drilled for the shank, so it will run in a back 
rest, and after doing this, put the end to be 
drilled into the back rest and the other end on the 
centre of your lathe, and drill the hole for the 
shank. When you have done this, take it out 
of the back rest, and using the hole for a cen- 
tre, turn it to fit the drill, put a set screw in it, 
and it is done. 



54. Making drills. 

There are numerous styles of drills. Every 
drill should be made straight on the sides of 
the lips, for at least half an inch from the end 
This prevents their running under or to on 
side. To this rule, however, we will except 
very small drills, as they would, if made in this 
way, soon get broken by the small particles of 
iron dust that force their way between the sides 
of the drill, and the sides of the hole being 
drilled. 



55. Spiral drills. 

To make a spiral drill, anneal it and turn it 
one-fiftieth of an inch larger than you intend it 



• 



52 THE BOSTON MACHINIST. 

to be, when finished. Then heat it again, and 
anneal it in a perpendicular position, either by 
putting it into lime or ashes in an upright po- 
sition, or dipping it into soap-suds. After 
doing this, turn the shank to fit a certain col- 
let socket or chuck (the names are various in 
different shops), and after doing this, you may 
turn the point or end to the desired shape and 
size. Then measuring from that point, turn it 
tapering, one-hundredth of an inch smaller, for 
every two inches of the drill's length, and the 
turning part is done.* 

* The reason for again heating a piece of steel after par- 
tially turning it, is simply because it is often hammered 
harder on one side than the other, and the turning it true, 
frequently takes more stock on one side than the side oppo- 
site. This leaves the side from which the lightest chip is 
taken much harder than the other, and this is the principal 
cause of a reamer or other slender tool's springing when it 
is hardened. Again, annealing tools in a perpendicular 
position is better than to lay them on their sides, for the rea- 
son that they sometimes he with their weight at each end, 
and this will always spring a reamer, or other slender tool. 
Almost everyone has seen a board lie with its weight 
resting upon its two ends, and that its own weight caused 
it to settle in the middle. Upon this principle, a piece of 
steel will settle when annealing, if not placed in a proper 
position. But if dipped into the water perpendicularly, the 
result will be, that when it is hardened, it will spring or 
strain itself to its proper position. 



THE BOSTON MACHLNJ 53 

56. Catting the Spiral < < •?. 
This is done in a machine made for the pur- 
pose, which contains a spindle, which revo! 
slowly while the grooves are being cut. This 
spindle also slides slowly, while grooves are 
being cut, and contains a screw, upon the 
of which is fastened a chuck, for holding the 
drill. You will put your drill into this chuck, 
and raise the sliding block which La beneath 
drill, until it touches the drill, takin not 

to raise it too high, so that the drill shall 
raised above the centre of the chuck into which 
it is screwed. Having adjusted your machine, 
you will put in a cutter, and groove your drills 
as follows: for drills one eighth of an inch in 
diameter, cut them two to the inch, calculal 
as you would in cutting a 8C1 i an engine 

lathe, and the depth of the groo >uld be 

cut to within one hundredth of an inch of the 
centre of the drills. For drills one half an i 
in diameter, one and a half to the inch, 
down to within a sixty-fourth of tl litre. 

Drills one inch in diameter, should be cut one 
to the inch, and down to a thirty-second of the 
centre. The index plate will give you the two op- 
posite points from which to commence cutting. 

5* 



54 THE BOSTON MACHINIST. 

The thickness of the cutter should be one 
half the diameter of the drill, and the edge of 
the cutter or teeth should be rounded to a per- 
fect circle. 

57. Flat Drills for Chucking. 
Such drills should be made of three lengths 
only. That is : when a lot is made for a shop, 
all sizes of three-fourths of an inch and above, 
should be made fifteen inches long. All sizes 
from three-fourths, down to three-eighths of an 
inch, ten inches, and sizes below that, five 
inches long. This saves the time usually lost 
in moving your puppet, when drilling your 
hole with several differently sized drills. As 
these drills are made to be followed by certain 
sized reamers, they should be made exactly 
one hundredth of an inch, at their ends, smaller 
than the reamer designed to follow them, and 
should be tapering, so as to measure, at a dis- 
tance of three inches from the points, one hun- 
dredth of an inch smaller than at the point. 
Eun this taper to the centre. Draw-file the edges, 
the same shape as turned by the lathe. Such 
drills should never have their edges filed square, 
as they are made in some country shops, for it 
is impossible to drill two holes of a size, with 






THE BOSTON MACHINIST. 55 

drills made in this way. The more nearly 
square such drills are made on their ends, the 
longer they will wear. It is necessary, how- 
ever, to take off the corners. In hardening 
such drills, it is not necessary to draw the tem- 
per, as they never break, and it is my philoso- 
phy never to draw the temper of a tool tli 
not liable to break, for the harder they are, the 
longer they will wear. 

58 Tap and Reamer Wrenches, 

Tap and reamer wrenches should be made 
square in the middle, and should have a square 
hole punched, or cut, through the square, to 
hold the head of the tap, or reamer, while 
the ends should be turned round, to within 
half an inch of the hole in the middle. 

59. Proportions for Tap and Reamer Wr 

Very small taps should be used in file 
handles. Wrenches for taps, and real 
one-eighth of an inch to five-sixteenths, should 
be five inches long, with a square in the mid- 
dle half an inch in diameter, and a square hole 
cut through it, three-sixteenths in diamel 
The ends are to be turned rounding, half an 
inch at extreme ends, and five-sixteenths near 



56 THE BOSTON MACHINIST. 

the hole in the middle. The extreme ends 
should be rounded with a hand tool and polish- 
ed, so as not to hurt the hands of the user. 

60. Tap and Reamer Wrenches, Size two. 
"Wrenches for taps, and reamers, from five- 
sixteenths to seven-sixteenths, should be ten 
inches long, with a square in their middle five- 
eighths in diameter, and a square hole through 
square, five-sixteenths diameter. Ends round, 
five-eighths by seven-sixteenths. 

61. Tap and Reamer Wrenches, Size three. 

Wrenches for taps and reamers, from seven- 
sixteenths to five-eighths, should be fifteen 
inches long. Square in middle, seven-eighths. 
Hole through square, seven-sixteenths. Ends 
turned rounding, three-fourths by nine-six- 
teenths. 

62. Wrenches for Taps and Reamers, Size four. 
Wrenches for taps and reamers, from five- 
eighths to thirteen-sixteenths, should be twenty- 
four inches long. Square in middle, seven- 
eighths by one and one-eighth inches. Hole 
through largest way five-eighths. Square ends, 
turned seven-eighths by eleven-sixteenths. 






THE BOSTON MACHI 




17.— A V-Tli' t-w. 18.— A Screw for gr .gth. 




19.— A Square Thread Screw. 



58 THE BOSTON MACHINIST. 

63. Wrenches for Taps and Reamers, Size five. 

Wrenches for taps and reamers, from thir- 
teen-sixteenths to one inch, thirty inches long. 
Square in middle, seven-eighths by one and 
three-eighths. Hole in square, thirteen-six- 
teenths. Ends, round, seven-eighths by three- 
fourths. 

64. Wrenches for Taps and Reamers, Size six. 

Wrenches for taps and reamers, from one 
inch to one and a fourth, forty inches long. 
Square in middle, one inch and five-eighths by 
one inch. Hole through square, one inch. 
Ends turned, one inch by seven-eighths. 

65. Making Taps. The Turning. 

This is a process requiring care, and every tap 
should have immediately under its head, or 
square for the wrench, a place turned exactly 
the size of the outside of the thread. You have 
then no trouble in getting the size of the 
threads, when they have an odd number of 
flutes in them. Every tap should also be 
exactly the size of the bottom of the thread, 
from the termination of the thread, which is 
usually about middling, to within about half an 



THK BOSTON MACHINIST. 59 

inch of the head, or square. This you will 
leav get the size of the outside of the 

thread, as aforesaid. It is a foolish error in 
tool makers, to make a iff above the 

termination of the thread, for the reason, that 
when in tapping a hole you come to a sudden 

>, the tap is sure to break; when, if it f 
turned straight from the terminus of the thr 
nearly up to the head, it would tw 
of break i 1 

66. P 

The sizes mark half an inch, in I 

echedul in proportion to tk h of 

the an- mostly used wit 

screw-driver. I think them fully 
threaded enough for all purp I im- 

bers marked coarser tli, n to the inch, are 

calculated for square-thi 
Screws of one-sixteenth indiameti j to 

the ineh. 

Screws of one-eighth in dial forty 

threads to the inch. 

Screws of three-sixteenths in diameter, thirty 
to the inch. 

Screws of one-fourth in diameter, twenty -five 
to the inch. 



60 THE BOSTON MACHINIST. 

Screws of five-sixteenths in diameter, twenty 
to the inch. 

Screws of three-eighths in diameter, seven- 
teen to the inch. 

Screws of seven-sixteenths in diameter, four- 
teen to the inch. 

Screws of half an inch in diameter, twelve to 
the inch. 

Screws nine-sixteenths in diameter, twelve 
to the inch. 

Screws five-eighths in diameter, eleven to 
the inch. 

Screws eleven-sixteenths in diameter, eleven 
to the inch. 

Screws three-fourths in diameter, ten to the 
inch. 

Screws thirteen-sixteenths in diameter, ten to 
the inch. i 

Screws seven-eighths in diameter, nine to 
the inch. 

Screws fifteen-sixteenths in diameter, nine to 
the inch. 

Screws one inch in diameter, eight to the inch. 

Screws one inch and one-sixteenth diameter, 
eight to the inch. 

Screws from one and one-eighth to one and 
one-fourth in diameter, seven to the inch. 



THE BOB] L0H1NI8T. 61 

Screws from one and one-eighth to one and 
One-fourth of an inch in diarn< the 

inch. 

■ s from one and five to one and seven- 
sixteenths in diameter, six threads to the inch. 

Screws from one and a half to one ; 
eleven-sixteenths in diameter, five thn 
the inch. 

Screws from one and three-fourths to I 
inches in diameter, four threads to the inch. 

67. Outti I 

V-thread taps should I with a 

exactly three-square. Some contend that they 
should lepth <>f their pi it I 

consider ti [uare tl 

n the I 

They should he finished with a shan 
the threads should never be polished in the 
threads, as the polish produc the 

iron, or steel, while tapping, — which would 
be the case, were it left rough. In cuttii 
tap for ordinary machine screws, or 
should measure with a pair of sharp callij 
the bottom of the thread of one of the scr« 
and cut your tap at the bottom of the thread, 
the same size. As the sizes of the scr 

6 



62 



THE BOSTON MACHINIST. 



\.S\rS' 




<M 



20. — Side view of a Square Thread-Tap. 



THE BOSTON MACHINES 

are so irregular, this is the B ray to get 

a fit. 

68. Square Thread-screws. 

Taps for square threads* -igned for 

strength, should be cut one-half the depth of 
their pitch. Therefore, if your thread is five 
to the inch, you will cut it one-tenth of an inch 
deep. Your threads being five to the inch, 
there would be a space between the threads one- 
tenth of an inch, and the thread being one- 
tenth wide, and one-tenth d \ ould form the 
square thread. Square tin r, how- 
ever, should be cut three-fourths tli b of 
their pitch. 

69. Mongrel^ or half ]" half square Threa 

These threads, made for gnat wear, are diffi- 
cult to cut. They should be cut the depth of 
their pitch, and for extra great wear, where a 

screw is required to be kept accurate for a l< 
time — such as the lead screw for a lathe, — they 
should be cut one and a half the depth of their 
pitch. The outside of the thread, also the bot- 
tom of the thread, should be in width, one- 
fourth of the thread's pitch. Therefore, if you 
were cutting a screw, five to the inch, it should 



64 THE BOSTON MACHINIST. 

be one-twentieth in width on the outside, and 
one-twentieth at the bottom of the thread. 

70. Fluting Taps. 

Every tap should be fluted with the teeth a 
little hooking on the face. That is, in strik- 
ing a line through the middle of the tap, on 
the end, the flute or groove should be inside 
that line, while the flute at the outside of the 
thread is exactly on the line. The back side of 
the teeth, however, may lean a little outside of 
the centre, but not enough to allow the dust to 
ride over, when backing out the tap. It is 
needless to say that it is impossible, in steel, to 
cut a coarse thread full with a tap, that has the 
faces of its teeth leaning backwards, without 
tearing out half the threads, for taps, made with 
the faces leaning backwards, do not cut, they 
merely stretch and tear the thread to its size, 
instead of cutting it. It is, in fact, upon the 
principle of turning a shaft with a square end 
tool, with the point or end leaning downwards. 

71. How to go to ivorlc. 
Set your tap on the centres, and with a cut- 
ter or planing tools made round at the end, and 
the thickness of the end one-fourth the diame- 



THE BOSTON MACHINIST. 65 

tcr of the tap. Plane the faces of all the teeth, 
one-half the depth of the thread below the bot- 
tom of the thread. For instance, if a thread is 
an eighth of an inch deep, plane or mill it one- 
sixteenth below the bottom of the thr< 
After planing all the faces, or milling them all 
to their depth, plane or mill off the back sides 
of the teeth, leaving them one and a half the 
breadth of their pitch. Thus, if the pitch is 
ten, leave them a tenth, and a twentieth. T 
leaves fully stock enough for strength, and the 
less bearing a tap has, the more easily it tu 
The back sides of the teeth should be i 
with a cutter, or planing tool, made in thick 
of the size of the tap. It is economical to 1 
two taps for every thread, and have the I 
one small enough to cut only two-thirds of the 
thread, and the second to finish. Taps, for 
five threads, made in this way, need no taper. 
They never go hard, and do not get broken, 
half so often, as when they are both of a E 
Very large mongrel thread taps should alw 
be of two sizes, at least, for the threads beii. 
coarse, and there being so much metal to 
cut out, it would be almost impossible to 
cut the thread otherwise, without tearing 
them. For hardening and tempering taps, 

6* 



22. 



23. 




THE BOSTON MACHINIST. 67 

see articles on "Hardening and tempering 
tools." 

72. Fluted Reamers. 
Fluted reamers should first be turned to with- 
in a thirty -second of an inch of the required 
size, and then heated and allowed to cool ii 
upright position, before finishing. This takes 
out the strains, and the hardness • in 

places by hammering out, so that they will 
not spring when heated for hardening. In Sat- 
ing reamers, merely fluting them with an 
number in view of preventing tl, shat- 

tering, is not sufficient For when 
chatters, it jumps from lip to lip; hence it is 
necessary to make the lips uneven. Flutes in 
reamers from one-fourth to 1i itlis of an 

inch in diameter, should be five. The number 
in reamers from five-eighths to one inch, should 
be seven. The number in r< from one 

inch to one and a fourth, should be nine. The 
number from one and a fourth to one and a 
half inches should be eleven. 

73. How to make a Fluted II 
Have the head forged to fit a certain wrench. 
Then make good centres in it, for these are ne- 






68 THE BOSTON MACHINIST. 

cessary to keep it true. Turn it to within a 
thirty-second of the required size, then heat it 
and let it cool in an upright position. Then, 
turn the part designed for the lips, one-hun- 
dredth of an inch larger than the size at which 
you intend to finish it, then turn a place in the 
middle of it five-eighths long, and one-twelfth 
of the reamer's size, smaller than it is. This is 
the place to pene it straight, after hardening. 
After turning all but the upper part (which is to 
be turned after it is hardened and straightened), 
you commence fluting it, by putting it on the 
centres, -and if you flute it on a planer, use a 
round-end tool, one- tenth of an inch in thick- 
ness, and plane it down to the face of every 
lip, down to the bottom of the place made for 
pening, and plane them so that in every other 
two of the lips, the space between them will be 
shorter than that of the two preceding them. 
After doing this, use a square end tool, and 
plane off the back side of the lips, up to within 
a thirty-second of an inch of the face. The 
faces of these lips should be planed straight 
with the centre. File the lips smooth, then 
harden it. For hardening it again, see articles 
on " Hardening and tempering tools." Then 
pene it straight. Then, turn the upper part to 



THE BOSTON MACHINIST. 



69 



24. 



25. 




THE BOSTON MACHINE 71 

the size required and polish it. And then 
grind the lips down to size, and have them 
sharp, and it is finished. 

74. Half-round Reamers. 

Half-round reamers should never be made, 
in this age, but should be superseded by a sin- 
i reamer, made in the following style, 
a piece of steel, and have the head forged, 
for a certain wrench, and as single-li] 
ers usually taper, turn it t; _ r , and perfect- 

ly round. Then put it on centres, and with a 
small round point tool, plane a groove ihn 
the whole length of it. One side of this 
groove forms the li] on from u 

plape off l irth of an inch, half \ 

round. File up the lips, on a line 

through the centre, on the end. Harden and 
temper, and it is done. 

75. Base Ream 

These reamers are only used for boring out 
holes that have b en cored, and cannot other- 
wise be drilled. They sometime a hole 
through them, and are, where large < 
quired, generally fitted upon an iron shaft, 
which is afterwards turned off to the same size 



72 THE BOSTON MACHINIST. 






as the reamer. Their ends should be square, 
with the corners taken off. Their lips should 
be cut about nine to the inch, on the end, and 
a little hooking. Harden the same as other 
reamers. 

76. Counter-boring Tools. 

To make a counter-boring tool, first fit the 
shank to a certain collet, then turn the govern- 
or, which should not be more than a quarter of 
an inch long, and after this, turn a place for the 
lips, about three-eighths of an inch long, on 
small ones, and about three-fourths on large 
ones. Beyond this place, turn it about one- 
third larger than the governor, and straight, up 
to the shank, by leaving the place for the lips 
short, and thus, it saves filing. You will then 
file four lips in them spiralling, like a drill, then 
file off the back side of the lips on the end, up 
to an edge, harden, and it is done. Flat coun- 
ter-boring tools are only made by ignoramuses, 
who break as fast as they make them. 

77. Making Dies for Screw-cutting. 

In making dies for screw-cutting, they 
should, wherever practicable, be lapped with a 
taper tap, as they cut more easily and wear 



Tin: B HACHlNIf 

. than those which are cut jbt, and 

ed oif, to make the screw "tal. 
Very fine tl. it well 

with straight did iall dies, or d low 

irth of an inch in size, should 
three lips In them. Dies from one-fourth to 
-half should have* four lips in them. Dies 
ii three-fourths to one inch should h. 
lips in them; and dies from an inch to an i 
and a half should have - lips in them. 

cuts through dies Bhou only twice the 

the tl t to 

make them free th m chi] 

:i cut i- o deep they are liable to to 
on the fa 11 raw 

oolo 

78. M 
Thin millii Is or cutl should be 

chucked to ii 'von the arbor of the ma- 

chine, in order that they may not be mall 

r hardening. Thev should then rned 

to within a thirty-second of th 

3, and then. tin heated before finishing. 

The heating a second time takes out the strains 
and hard pla< that they arc .able to 

spring when heated for hardening. 

7 



74 THE BOSTON MACHINIST. 

79. Proportionate numbers of Teeth, in different 

sizes. 

The number of teeth to the inch in different 
cutters, should vary in proportion to their sizes. 
Very thin cutters of all sizes should be cut 
very fine, as they are very easily broken when 
the teeth are coarse. The following list will 
probably give as good proportions as can be 
well arrived at. At least I have spent consi- 
derable time in " figuring them out," andean 
find none that I think better. 

Cutters one-tenth of an inch thick, should 
have thirty teeth to the inch for large sizes, 
and thirty-five for small sizes. 

Cutters from one-eighth to three-sixteenths 
in thickness, should have twenty-five to the 
inch for large sizes, and thirty for small sizes. 

80. Proportions of Broad Gutters. 

Cutters half an inch in diameter, should be 
cut thirty to the inch; and contain eighteen 
teeth, of one-sixteenth of an inch deep. 

Cutters three-fourths of an inch in diameter, 
should be cut thirty- two to the inch and con- 
tain twenty -four teeth of one-fifteenth of an 
inch deep. 



THE BOSTON MACHINE 

Cutters one inch in diameter, should be cut 
tie inch, and contain twen 
i, of one-fourteenth of an inch de< 
Cutters one and a half inches in diameter, 
should be cut tv. our teeth to the ii 

and contain thirty side teeth, one-twelfth of an 
inch 

:wo inches in diameter, should be 
cut tw< th to the inch, and contain forty 

h, cut one-tenth of an inch de 
Cutters three inches in diamet 
sixteen to the inch, and contain forty-eight 
..th of an inch deep. 
Cutt« r inches in dian ild be 

thirteen to I contain fifty-two teeth, 

cut i .th of an inch 

Cutt ra five in in dian -hould be 

i to the inel . contain fifl 

. rut one-fifth of an inch de 
Cuttei inches in diameter, should be cut 

ten to the inch, and contain . cut 

an inol th of tl 

cutters should always be cut hooking, and the 
zes should be left near nth of 

an inch thick at the edge. The outer surface 
of the cutter should be draw-filed nearly 
square with the fac< cut more 



76 THE BOSTON MACHINIST. 

smoothly than when filed too sharp. Harden, 
and draw to a straw color. 

81. Punches and Dies. 

In making these, it is necessary to fit the 
piece intended for the die into the slide or 
plate of the punch, and } r ou may then put it 
in its place, and run the slide which holds the 
punch, down upon it. This slide is nearly 
round, and you may, after running it down, 
mark around it upon the piece intended for 
the dies, and cut your die, so the centre of it 
will come in the centre of the place marked on 
it. The die should be cut through square with 
its face. Such dies should be made higher 
in the centres, or where the hole is cut 
through, than its general surface, in order 
that they may be ground off when dull; After 
finishing the die, harden it, and put it into its 
place. Then fit the shank of the piece intend- 
ed for the punch into the slide, then put the 
punch into the slide, and run it down upon the 
die. Then mark through the die, on the end 
of the punch, its desired shape. Then take 
out the punch and cut it down very nearly 
to the mark, and you may then put the punch 
into the machine again, and press it into the 



Til MACHINIST. 77 

die an i i_ r iith of an inch, and tliis will : 
ipe perfectly. Harden, and it is finished. 

82. Mai tuges. 

In the making of gauges, or forms for cut- 
or drilling machinery, it would be impos- 
sible to give any correct details, as the styles and 
shapes are too numerous, and I can only - 
that it is i) ave them enough larger 

before hardening, to allow for what they will 
contract, or spring, when hardening. A 
hardening, they should be ground, 00 DM 
nery made for the purp 

Gauges for drilling may be m * their pro- 

per size b harden a they cannot be 

ground after hardening. 

83. M 
Although balance-wheels have been Died for 
3, the mode of applying them 
seemed never to hi >wn. I there- 

fore endeavored I rtain this, and ha 

I that every balance-wheel should be 
speeded up, so as to run twice or three timet 
last as the crank-shaft it is intended to balance; 
and that where a balance-wheel is applied in 
this way, it makes the machine run a great 



THE BOSTON MACHINIST. 

deal more steadily, for when the balance-wheel 
is geered into the crank-shaft, and runs two or 
three times faster than the crank-shaft, it forms 
a power of itself, when going over the centre, 
which propels the crank-shaft until it reaches 
the quarter where it again takes its power from 
the machine. Although it takes an additional 
shaft and geers to apply a balance-wheel in 
this way, the saving of metal in the balance- 
wheel fully compensates for the extra labor, 
for when a balance-wheel is speeded three 
times as fast as the crank-shaft, it needs only 
one-third of the metal in it that it would, were 
it not speeded up at all, and if balance-wheels 
were applied in this way generally, it would 
make all engines run far more steadily. 

84. A few words as to Master Mechanics. 
It may safely be said that not one master me- 
chanic in twenty knows his business thorough- 
ly. ' Nineteen of that twenty will only buy 
such heavy tools as he is forced to have in or- 
der to do his business, and then, for the want 
of a few small tools, that would cost compara- 
tively nothing, some cotton waste with which 
to keep them clean, and a little care to see 
that it is done, his shop will be encumbered 



MACHINE 

ibbish and filth, his lath mill- 

machint, etc., etc., coy ith grease, so 

>r use, and his men spend one- 
third of their time, looking for a bolt, strap of 
iron, or some other petty thing, of >>rth 

than the time Spent in lookii:_ r them. 

the s to ruin. 

1 all this, for the want of a superintendent 

on 
duty. Th do not aj 

shops v. 

vn that they are The 

•hanic who knows his ] loroughly, 

will have every tool kept e ad in ItE 

will hav dent number of t 

lath ; rill and | tools, with all 

other small t- i that ii<^ man i. ait a 

moment for want of them: for "tine 
money." He will keep hifl 
and drills, as near the machines they are q 

ble, and ti. e trouble, and 

more likely to ensure them in their plfl 
lie should have lor every planer, hah" a do- 
zen straps, made of one inch by half an inch 
iron, and bent in a D sha: ai enough 

gether to hold a three-fourths inch bolt. 
These straps need no drilling for the bolt, and 



THE BOSTON MACHINIST. 



are far more "bandy" than straps witb boles 
drilled through them. He should have three- 
fourths inch bolts, of a dozen sizes, witb nuts 
an inch thick, in order to prevent stupid work- 
men from stripping them. He should see that 
the centres of arbors, w T hen made, are counter- 
sunk, perfectly three-square, and that the cen- 
tres of the lathes likewise are kept perfectly 
three-square. Unless he does this, the arbors 
will spoil the centres of the lathes, and the cen- 
tres of the arbors will soon w r ear out of true r 
and the arbors thus be rendered worthless. He 
should have plenty of drills, so they need not 
be altered every time he has a new hole to drill. 
He should have holes for drills in all small col- 
lets, of such a size, that one drill can be used in 
any part of the shop ; and the large ones like- 
wise. 






